Gael lowig



UNITED STATES PATENT OFFroE;

CARL LOWIG, OF BRESLAU, PRUSSIA, ASSIGNOR TO FRIEDRICH LOEWIG, OF GOLDSGHMIEDEN, GERMANY.

IMPROVEMENT IN PROCESSES 0F OBTAINING SUGAR FROM THE JUICE 0F BEET-ROOT AND OTHER SACCHARINE LIQUIDS.

Specification forming part of Letters Patent N 0. 219,281, dated September 2, 1879 application filed April 29, 1879. I

To all whom it may concern:

Be it known that 1, CARL LoWIG, of Breslau, in the Kingdom of Prussia, have invented tain from them the greatest quantity of sugar possible.

This method is based upon the principle of removing the salts as much as possible, and of perfectly removing the organic non-sugar matters by means of materials which have such removing power without introducing any damaging new matters in place of the removed ones; and it consists in the treatment with lime and gelatinous alumina, as hereinafter described. I

I. Method of obtaining sugar from juice-l add to one thousand parts of juice at the ordinary temperature two parts, by weight, of lime, in the form of lime-water, and after several minutes I add about from 1.25 to 1.5 per cent. of alumina, in a gelatinous state. I then slowly raise the heat to from 60 to 70 Celsius, keep the mixture for several minutes up to this heat, and afterward separate the juice, by filter-presses, from the dark-colored aluminaslime created, which is easily effectuated. The separation will be a perfect one if a filtered sample of the mixture will not become cloudy by adding oxalic acid, or oxalate of ammonia, or a solution of sugar of lead mixed with a few drops of acetic acid. Should, however, a filtered sample of the mixture become cloudy, a small quantity of gelatinous alumina must be added to the juice.

The above-mentioned small addition of lime will cause no separation. It is added only for the purpose of obtaining a solution of limesugar.

Along with the action of the alumina, the

acids of the present salts (especially salts of potassa) will be precipitated, which, with the lime, will enter into insoluble combinations, and which will not be separated by the alumina alone, while the freed bases-that is, mainly the potassawill take the-place of the lime. The juice remains alkalized. The alkalinity, however, is caused by the potassa.

Simultaneously with the reaction mentioned, the alumina causes the precipitation of the excess of lime and the total amount of the organic non-sugar matters, colored as well as not colored, contained in the juice, and after the process of filtration by filter-presses a colorless or very slightly yellow-colored juice is obtained, which, as already mentioned, owes its alkalinity to the potassa. The juice is perfectly odorless, and possesses an agreeable sweet taste.

In some instances, if fluosilicic acid is tobe had, I prefer to saturate the alkaline juice with this acid, but not to perfection, which acid may be precipitated as fluosilicate of potassium, the removal or separation of which may easily and. in very short time be effected by means of adding a small quantity of gelatinous alumina. If no fluosilicic acid is to be had, I prefer adding to the juice a small quan tity of hyperhydrochloride of alumina, but with this precaution, that the juice remains alkaline.

The small quantity of alumina which is thereby separated will increase the purifica tion of the juice.

The juice obtained is now to be considered as perfectly purified, save of the present salts and the small quantity of potassa contained in the juice, and may be evaporated without further chemical treatment for crystallization. If, however, it is preferred to let the juice pass before crystallization through an animal-chap coal filter, the charcoal will act with all its efficacy upon the salts of the juice, as the latter contains neither lime nor organic matters, and the return in crystallized sugar will be increased in proportion to the removal of salts.

It is evident that the animal charcoal, having but very trifling quantities of impurities the process of filtration, and these matters will increase the formation of molasses. As, now, the gelatinous alumina will perfectly remove the lime as well as the organic non-su gar matters from the so-treated juice, it is evident that in removing from the juice before saturation and filtration over animal charcoal the lime and the organic non-sugar matters, by adding a proportionate quantity of gelatinous alumina, not only the saturation and the most disagreeable formation of slimy masses may be avoided, but also, after filtration over animal charcoal and the subsequent removal of salts, a juice is obtained which will be nearly as much purified as the juice obtained by the above-described separation by alumina.

The process of treating the juice with the gelatinous alumina is substantially the same as described for the first method but, of course, no lime is added.

III. Method of obtaining sugar from molasses. The molasses obtainedfor instance, in beetroot-sugarmills-accordingto the processhitherto in use, will contain, besides Water, sugar capable of crystallization, and sugar incapable of crystallization to a certain extent, the salts of potassium and organic matters, which latter may be precipitated by sugar of lead and gelatinous alumina. These latter ingredients of the molasses will prevent the crystallization of sugar. Now, in order to remove these matters, I dilute the molasses to from 40 to 45 Brix, and I add to this dilution, while cold, one per cent. of lime, and afterward add gelatinous alumina till a sample proof of the mixture, after warming, will not be rendered cloudy by a solution of sugar of lead. The molasses thus purified may henceforth be freed from a portion of its contents of salts by filtration over animal charcoal. The molasses, however, may advantageously be treated by the osmotic process, by which process nearly all the salts capable of crystallization may be removed, though with a small loss of sugar.

After evaporation a slightly-colored odor-,

less sirup of an agreeable sweet .taste will be obtained, of which, after a certain lapse .of time, a high percentage of sugar will crystallize.

I have found by experiment that from molasses treated thrice by the osmotic process, and delivering no more sugar after having been submitted to the purifying process with lime and alumina, according to my process nine per cent, in weight, of the molasses has been obtained as purified white sugar after filtration.

IV. Purification of the darhoolored osmotic sugar-Idissolve one hundred parts, by weight, of the dark osmotic sugar in two hundred parts of water, and to this solution I first add 1.5 per cent. of lime, and I then add such quantity of gelatinous alumina which may be found necessary for removing the contents of organic matters. The solution, of slightly yellow color, running from the filter-press, will,

after having passed the charcoal filter, deliver a perfect white sugar. I use the same process for purifying the dark by-products in sugar-mills or sugar-refineries.

' I claim The process herein described of clarifying and purifying saccharine liquids, the same consisting in first mixing lime-water with such liquids at the ordinary temperature, and afterward adding to the same gelatinous alumina, and raising the temperature of the liquid to about 60 or 70 Celsius, then separating the alumina-slime from the juice by filtering, substantially as set forth.

This specification signed by me this 19th day of November, 1878. n I

PROF. DR. CARL LOWIG.

Witnesses:

A. RABER, A. GERKHART. 

